/* -*- mode: c; indent-tabs-mode: t; c-basic-offset: 8; tab-width: 8 -*- */
/* vi: set ts=8 sw=8 sts=8: */
/*************************************************************************/ /*!
@File
@Title          PowerVR Linux software "counting" timeline fence implementation
@Codingstyle    LinuxKernel
@Copyright      Copyright (c) Imagination Technologies Ltd. All Rights Reserved
@License        MIT

The contents of this file are subject to the MIT license as set out below.

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

This License is also included in this distribution in the file called
"MIT-COPYING".

EXCEPT AS OTHERWISE STATED IN A NEGOTIATED AGREEMENT: (A) THE SOFTWARE IS
PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING
BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
PURPOSE AND NONINFRINGEMENT; AND (B) IN NO EVENT SHALL THE AUTHORS OR
COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/ /**************************************************************************/

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/kref.h>

#include "services_kernel_client.h"
#include "pvr_counting_timeline.h"
#include "pvr_sw_fence.h"

#define PVR_DUMPDEBUG_LOG(pfnDumpDebugPrintf, pvDumpDebugFile, fmt, ...) \
	do {                                                             \
		if (pfnDumpDebugPrintf)                                  \
			pfnDumpDebugPrintf(pvDumpDebugFile, fmt,         \
					   ## __VA_ARGS__);              \
		else                                                     \
			pr_err(fmt "\n", ## __VA_ARGS__);                \
	} while (0)

struct pvr_counting_fence_timeline {
	struct pvr_sw_fence_context *context;

	void *dbg_request_handle;

	spinlock_t active_fences_lock;
	u64 current_value; /* guarded by active_fences_lock */
	u64 next_value; /* guarded by active_fences_lock */
	struct list_head active_fences;

	struct kref kref;
};

struct pvr_counting_fence {
	u64 value;
	struct dma_fence *fence;
	struct list_head active_list_entry;
};

static void
pvr_counting_fence_timeline_debug_request(void *data, u32 verbosity,
			DUMPDEBUG_PRINTF_FUNC *pfnDumpDebugPrintf,
			void *pvDumpDebugFile)
{
	struct pvr_counting_fence_timeline *timeline =
		(struct pvr_counting_fence_timeline *)data;
	struct pvr_counting_fence *obj;
	unsigned long flags;
	char value[128];

	if (verbosity == DEBUG_REQUEST_VERBOSITY_MEDIUM) {
		spin_lock_irqsave(&timeline->active_fences_lock, flags);
		pvr_sw_fence_context_value_str(timeline->context, value,
					       sizeof(value));
		PVR_DUMPDEBUG_LOG(pfnDumpDebugPrintf, pvDumpDebugFile,
				  "sw: %s @%s cur=%llu",
				  pvr_sw_fence_context_name(timeline->context),
				  value, timeline->current_value);
		list_for_each_entry(obj, &timeline->active_fences,
				    active_list_entry) {
			obj->fence->ops->fence_value_str(obj->fence,
							 value, sizeof(value));
			PVR_DUMPDEBUG_LOG(pfnDumpDebugPrintf, pvDumpDebugFile,
					  " @%s: val=%llu", value, obj->value);
		}
		spin_unlock_irqrestore(&timeline->active_fences_lock, flags);
	}
}

struct pvr_counting_fence_timeline *pvr_counting_fence_timeline_create(
	void *dev_cookie,
	const char *name)
{
	PVRSRV_ERROR srv_err;
	struct pvr_counting_fence_timeline *timeline =
		kmalloc(sizeof(*timeline), GFP_KERNEL);

	if (!timeline)
		goto err_out;

	timeline->context = pvr_sw_fence_context_create(name,
							"pvr_sw_sync");
	if (!timeline->context)
		goto err_free_timeline;

	srv_err = PVRSRVRegisterDbgRequestNotify(&timeline->dbg_request_handle,
				dev_cookie,
				pvr_counting_fence_timeline_debug_request,
				DEBUG_REQUEST_LINUXFENCE,
				timeline);
	if (srv_err != PVRSRV_OK) {
		pr_err("%s: failed to register debug request callback (%s)\n",
		       __func__, PVRSRVGetErrorStringKM(srv_err));
		goto err_free_timeline_ctx;
	}

	timeline->current_value = 0;
	timeline->next_value = 1;
	kref_init(&timeline->kref);
	spin_lock_init(&timeline->active_fences_lock);
	INIT_LIST_HEAD(&timeline->active_fences);

err_out:
	return timeline;

err_free_timeline_ctx:
	pvr_sw_fence_context_destroy(timeline->context);

err_free_timeline:
	kfree(timeline);
	timeline = NULL;
	goto err_out;
}

void pvr_counting_fence_timeline_force_complete(
	struct pvr_counting_fence_timeline *timeline)
{
	struct list_head *entry, *tmp;
	unsigned long flags;

	spin_lock_irqsave(&timeline->active_fences_lock, flags);

	/* This is just a safety measurement. Normally we should never see any
	 * unsignaled sw fences when we come here. Warn if we still do! */
	WARN_ON(!list_empty(&timeline->active_fences));

	list_for_each_safe(entry, tmp, &timeline->active_fences) {
		struct pvr_counting_fence *fence =
			list_entry(entry, struct pvr_counting_fence,
			active_list_entry);
		dma_fence_signal(fence->fence);
		dma_fence_put(fence->fence);
		fence->fence = NULL;
		list_del(&fence->active_list_entry);
		kfree(fence);
	}
	spin_unlock_irqrestore(&timeline->active_fences_lock, flags);
}

static void pvr_counting_fence_timeline_destroy(
	struct kref *kref)
{
	struct pvr_counting_fence_timeline *timeline =
		container_of(kref, struct pvr_counting_fence_timeline, kref);

	WARN_ON(!list_empty(&timeline->active_fences));

	PVRSRVUnregisterDbgRequestNotify(timeline->dbg_request_handle);

	pvr_sw_fence_context_destroy(timeline->context);
	kfree(timeline);
}

void pvr_counting_fence_timeline_put(
	struct pvr_counting_fence_timeline *timeline)
{
	kref_put(&timeline->kref, pvr_counting_fence_timeline_destroy);
}

struct pvr_counting_fence_timeline *pvr_counting_fence_timeline_get(
	struct pvr_counting_fence_timeline *timeline)
{
	if (!timeline)
		return NULL;
	kref_get(&timeline->kref);
	return timeline;
}

struct dma_fence *pvr_counting_fence_create(
	struct pvr_counting_fence_timeline *timeline, u64 value)
{
	unsigned long flags;
	struct dma_fence *sw_fence;
	struct pvr_counting_fence *fence = kmalloc(sizeof(*fence), GFP_KERNEL);

	if (!fence)
		return NULL;

	sw_fence = pvr_sw_fence_create(timeline->context);
	if (!sw_fence)
		goto err_free_fence;

	fence->fence = dma_fence_get(sw_fence);

	spin_lock_irqsave(&timeline->active_fences_lock, flags);

	fence->value = timeline->next_value++;

	list_add_tail(&fence->active_list_entry, &timeline->active_fences);

	spin_unlock_irqrestore(&timeline->active_fences_lock, flags);

	/* Counting fences can be signalled any time after creation */
	dma_fence_enable_sw_signaling(sw_fence);

	return sw_fence;

err_free_fence:
	kfree(fence);
	return NULL;
}

bool pvr_counting_fence_timeline_inc(
	struct pvr_counting_fence_timeline *timeline, u64 value)
{
	struct list_head *entry, *tmp;
	unsigned long flags;
	bool res;

	spin_lock_irqsave(&timeline->active_fences_lock, flags);

	if (timeline->current_value == timeline->next_value-1) {
		res = false;
		goto exit_unlock;
	}

	timeline->current_value++;

	list_for_each_safe(entry, tmp, &timeline->active_fences) {
		struct pvr_counting_fence *fence =
			list_entry(entry, struct pvr_counting_fence,
			active_list_entry);
		if (fence->value <= timeline->current_value) {
			dma_fence_signal(fence->fence);
			dma_fence_put(fence->fence);
			fence->fence = NULL;
			list_del(&fence->active_list_entry);
			kfree(fence);
		}
	}

	res = true;

exit_unlock:
	spin_unlock_irqrestore(&timeline->active_fences_lock, flags);

	return res;
}